Thunnus thynnus
Thunnus thynnus (''Atlantic bluefin tuna)' Kingdom: '''Animalia Phylum: Chordata Class: Actinopterygii Order: Scombriformes Family: Scombridae Genus: Thunnus Species: Thunnus thynnus Environment: milieu, climate zone, depth range, distribution range: Marine; brackish; pelagic-oceanic; oceanodromous; depth range 0 - 985 m, usually 0 - 100 m. Subtropical; 3°C - 30°C; 76°N - 58°S, 99°W. Distribution: Western Atlantic: Labrador and Newfoundland to Gulf of Mexico, and Caribbean Sea to Venezuela and Brazil. Eastern Atlantic: Lofoten Islands off Norway to Canary Islands, including the Mediterranean and the southern part of the Black Sea. Reported from Mauritania. There is a subpopulation off South Africa. Highly migratory species, Annex I of the 1982 Convention on the Law of the Sea. Size, weight, age: Max. length: 4.58 m, common length: 2 m; weight: 684 kg; age: 32 years Short description: A very large species, deepest near the middle of the first dorsal fin base. The second dorsal fin higher than the first; the pectoral fins are very short, less than 80% of head length. Swim bladder present. Lower sides and belly silvery white with colorless transverse lines alternated with rows of colorless dots. The first dorsal fin is yellow or bluish; the second reddish-brown; the anal fin and finlets dusky yellow and edged with black; the median caudal keel is black in adults. May be confused with several other tunas, these are typically much smaller and easily distinguished by specific patterns of stripes, bands or dots. Biology: Oceanic but seasonally coming close to shore. They school by size, sometimes together with albacore, yellowfin, bigeye, skipjack etc. Visual predators preying on small schooling fishes (anchovies, sauries, hakes) or on squids and red crabs. Live up to 40 years in the western Atlantic. Weight up to 900 kg. Eggs and larvae are pelagic. Juvenile growth is rapid (about 30 cm / year) but slower than in other tuna and billfish species. Adult growth is considerably slower, with about 10 years needed to reach two thirds of maximum length. Commercially cultured in Japan. Utilized fresh for sashimi, also canned. Become rare because of massive overfishing. Life cycle and mating behavior: Oviparous batch spawner, with an inter-spawning interval of 1-2 days in the Mediterranean Sea. Females larger than 205 cm fork length are estimated to have a mean fecundity of 30-60 and 13-15 million eggs, in the western and eastern Atlantic respectively. Spawning occurs when sea surface temperatures are between 22.6-27.5 ºC and 22.5-25.5 ºC in the Gulf of Mexico and Mediterranean Sea respectively. Spawning occurs between June and August in the Mediterranean Sea. Eggs are released directly to the water column and hatch after 2 days. At 24°C, embryo development lasts about 32 hours and larval stages about 30 days. Egg size 1.0 mm, larval length at hatching 2.8 mm. Spawning grounds are mainly known from the Gulf of Mexico and the Mediterranean Sea, but the presence of mature individuals and larvae far from these areas (e.g. Bahamas and central North Atlantic Ocean) suggest that other spawning grounds may also be utilized. Appears to display homing behaviour with (western-tagged individuals migrating back to specific spawning sites either in the Gulf of Mexico or the Mediterranean Sea). Fidelity to natal areas seem to occur once individuals reach maturity, i.e. after returning to either the western or eastern spawning grounds. Main reference: Collette, B.B., 1999. Mackerels, molecules, and morphology. p. 149-164. In B. Séret and J.-Y. Sire (eds.) Proc. 5th Indo-Pac. Fish Conf., Noumea, Paris. IUCN Red List Status: ENDANGERED (''EN)' '''CITES: Not Evaluated CMS: Not Evaluated Threat to humans: Harmless Human uses: Fisheries: commercial; aquaculture: commercial; gamefish: yes. Category:Scombridae, Mackerels, tunas, bonitos